There are an infinite number of such subsets. One of them is the set of real numbers in the interval (7, 8). Perhaps you're thinking "irrational" numbers, as opposed to "integers" or "rational" numbers.
(-5/8)(X) = -0.4
(-5/8)(X) = -4/10
X = (-4/10) / (-5/8)
X = (4/10) / (5/8)
X = (4/10)(8/5)
X = (2/5)(8/5)
X = 16/25
Letter D
It will be 5 out of 9 times you will pull a red marble
